Measurement systems and methods for measuring macroscopic quantities, such as quantities on the order of grams or kilograms, are well developed and readily available. However, as more scientists and engineers examine the microscopic properties of materials, the demand for microscopic and nano-scale measurements increases. This demand for the measurement of small quantities is further driven by the desire of many scientists and engineers to understand material properties that are derived from measurements related to small changes in the mass of materials.
Unfortunately, the measurement of small quantities of materials and changes in small quantities of materials presents difficult problems. Some of the problems result from the fact that many macro-measurement systems do not scale easily to the measurement of nano-scale quantities. For example, mechanical balances used in the measurement of macro-quantities may not be modifiable to provide accurate measurements in the nano-gram range. Additional problems, such as the degradation of samples with the passage of time, arise in the measurement of some samples, such as biological samples. Despite the difficult problems that must be solved to achieve nano-scale measurements, the demand for systems capable of measuring small quantities of materials continues to increase.